CelerisSystems
DEFINING %COMPLETE IN
MICROSOFT PROJECT
P REPARED
BY
James E Aksel, PMP, PMI-SP, MVP
For Additional Information about Earned Value Management Systems and reporting,
please contact:
CelerisSystems, Inc.
3335 East Mira Loma Ave, Suite 143
Anaheim, CA 92806
United States
Telephone: +1 714-813-4025 or 800-951-E3V8M6S7
http://www.Celeris-Systems.com
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Contents Table of Contents 1 Introduction ......................................................................................................................... 3 2 Background ......................................................................................................................... 3 3 Percent Complete Calcuation Types......................................................................................... 3 4 3.1 Percent Complete ............................................................................................... 3 3.2 Percent Work Complete ....................................................................................... 4 3.3 Physical Percent Complete ................................................................................... 5 Analysis .............................................................................................................................. 6 4.1 Duration Analysis (Detail Tasks) ........................................................................... 7 Equations Equation 1 Duration Based Percent Complete......................................................... 3 Equation 2 Percent Work Complete ...................................................................... 5 Equation 3 Physical Percent Complete ................................................................... 6 Figures Figure 1 Percent Complete Screen Shot ................................................................ 4 Figure 2 Resource Sheet ..................................................................................... 4 Figure 3 Resource Loaded Schedule Showing Total Work ......................................... 4 Figure 4 Work Profile (Task Usage View) ............................................................... 4 Figure 5 Percent Work Complete Screen Shot ........................................................ 5 Figure 6 Costed Resource Loading ........................................................................ 5 Figure 7 Physical Percent Complete Screen Shot .................................................... 6 Figure 8 Graphical Illustrations of Three Methods of Percent Complete....................... 7 Tables Table 1 Expected Values of Percent Complete ........................................................ 7 CelerisSystems
1
INTRODUCTION
The key to understanding percent complete is to recognize the value is a fraction. To
obtain a fraction, divide two numbers. This implies the user knows which two
numbers to divide: Bricks laid divided by total bricks required, wages paid divided by
total budget, work hours spent divided by total work hours estimated. Without
knowing which two numbers to divide, a percent complete is just a number for
misinterpretation by others. The real questions here are: “If I am on schedule, how
many bricks should I have laid? How many dollars in wages should I have paid? How
many work hours should have been expended? How much cost should I have
incurred?
2
BACKGROUND
Microsoft Project contains three measures of “%Complete.” Many users of the
software want to know: If they are on schedule, what should be the values
calculated by each of the measures of percent complete. The three measures are:
Percent Complete (%Complete), Percent Work Complete (%Work Complete), and
Physical % Complete. Additional measures are available if created by the user.
3
PERCENT COMPLETE CALCUATION TYPES
3.1 Percent Complete
The default method of measuring “%Complete” by Microsoft Project is based on
activity duration, a 10 day activity is 40% Complete at the close of business on the
4th work day from the start date of the activity. Microsoft Project will indicate this
task is “late” if the value for %Complete is less than the expected value as of the
status date. This information is viewable in either the status indicator or status
columns.
The formula to roll up %Complete for summary level tasks, and eventually the entire
project is given by:
∑
i =tasks
i =1
%Completei * Durationi
i = task
∑ Duration
i =1
i
Equation 1 Duration Based Percent Complete
Using Figure 1 below, Microsoft Project will calculate the percent complete as
follows:
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Figure 1 Percent Complete Screen Shot
%Complete = [(50%*(5 days) + 30%*(7 days) + 65%*(3 days)]/(5 days + 7 days + 3 days)
%Complete = 43.6667%
Microsoft Project will round to the nearest whole integer, 44%.
3.2 Percent Work Complete
Percent complete based on the number of work hours completed is another measure
calculated by Microsoft Project. For this purpose, two resources will be loaded to the
tasks with work as shown.
Figure 2 Resource Sheet
Figure 3 Resource Loaded Schedule Showing Total Work
The man-hour profile for work-hours is loaded with the majority of the work in the
first three days:
Figure 4 Work Profile (Task Usage View)
Percent work complete is calculated in accordance with an effort based weighting:
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i =tasks
%WorkComplete =
∑ %WorkComplete *Work
i =1
i
i
i =tasks
∑Work
i =1
i
Equation 2 Percent Work Complete
Using the same percentages as the original example, the calculation becomes:
%Work Complete= [50%*(40) + 30%*(14) + 65%*(12)]/[40+14+12]
%Work Complete=48.48%
Microsoft Project confirms the calculation:
Figure 5 Percent Work Complete Screen Shot
3.3 Physical Percent Complete
When the desired unit of measure is Physical Percent Complete, a baseline is
required and the calculation is based on the dollar costs involved. In this case, the
cost of the project is spread as shown below:
Figure 6 Costed Resource Loading
For the moment, the Project Status Date will be set far into the future, past the last
day of the project. In this case, although any measure of the three measures of
percent complete should indicate a behind schedule condition, the Physical %
Complete appears in the figure below:
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Figure 7 Physical Percent Complete Screen Shot
The equation used by Microsoft Project depends on the dollar value of the work
budgeted and is shown below:
∑
Physical %Complete =
i =tasks
i =1
Physical %Completei * BACi
i =tasks
∑ BAC
i =1
i
Equation 3 Physical Percent Complete
Note: BAC is Budget At Complete, Total Cost, or Baseline Cost.
The details of the calculation are:
Physical Percent Complete = [50%($3,440)+30%($1204)+65%(228)]/[$4872]
Physical Percent Complete = 46%
Further analysis regarding calculation of Physical % Complete is in a later section of
this paper. Specifically, what happens when the status date is before or during the
period of performance of tasks?
4 ANALYSIS
The previous section describes three methods of determining percent complete. In
each case, the value claimed for percent complete was numerically identical for the
three discrete tasks (50%, 30% and 65%, respectively). The weighted value of the
calculation produced a different result in each case at the summary level. In the
example, the values are close. However, consider what might happen if there was a
large discrepancy in the amount of work assigned to the tasks, or, if the costs of the
resources were vastly different from each other.
Further, the measures of percent complete (Duration, Work, and Physical) all
represent different things. Although the possibility does exist that the measures
could theoretically be equal under certain circumstances, the general case is the
measures will not be numerically equal. If a project marches along “on schedule”
the table below will show the cumulative % Complete for each calculation type:
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Table 1 Expected Values of Percent Complete
Method
%Complete
vs. Day
%Work
Complete
Physical
%
Complete
1
20
21
19
2
40
42
39
3
60
64
58
4
73
79
75
5
87
94
93
6
93
97
96
7
100
100
100
Graphically the results are different for each method of percent complete as a
function of time:
120
100
80
%Complete
60
%Work Complete
Physical % Complete
40
20
0
1
2
3
4
5
6
7
Figure 8 Graphical Illustrations of Three Methods of Percent Complete
4.1 Duration Analysis (Detail Tasks)
By definition, the duration percent complete of a task grows only with the passage of
time and is always on schedule. Since it is duration based measurement, unless the
task has not started and needs to be delayed, the user should always claim the tasks
to be “as scheduled” when updating the duration based percent complete. Where the
calculation will vary is when the user makes updates to the remaining work and
remaining duration fields. This author has no understanding of the concept a user
can claim any duration based %complete and then provide remaining duration
estimates that are inconsistent with the percent complete provided. In the case of
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duration based percent complete, it is best to adjust remaining duration (or
remaining work) and let the software calculate the percent complete. If the user
provides remaining work or duration greater than calculated by the program, the
%Complete value will regress. If the user revises the remaining duration/work to be
less than calculated by the program, the %Complete increases. Depending on the
reporting rules in place on the program, it may be a violation of reporting rules to
allow the percent complete to decrease from a prior reporting period.
If an estimator believes it will take three days to paint 24 feet of fence, the planned
profile will be 33% per day. If at the end of the first day the painter claims four
additional days are needed, then the job is 1/5 = 20% duration complete (1 day of
actual duration, 4 days of remaining duration).
What the user really wants to know is how the 20% complete calculation compares
to the 33% complete that is expected (the baseline). Indeed, what duration percent
complete is expected for the purpose of this comparison as of the status date (end of
day 1)? The answer is 33% and the painter met 20/33=61% of expectation (39%
behind schedule).
What can be done in a case such as this? If the task is originally assigned as fixed
units with one resource, then management needs to decide how to recover from the
given situation. There appears to be several choices:
•
Clearly the painter has re-estimated the job, perhaps because of
increased intelligence gained during the performance of Day1. The
painter provides a revised estimate to complete so the cost of the job
increases (from 24 hours to 40 hours). Management must decide if the
additional cost will be absorbed or passed on to the customer, and, if
the additional duration is acceptable to all the stakeholders.
•
Substitute a resource and assign the task to someone who can
complete the job within the remaining baseline duration (2 remaining
days). This may change costs.
•
Change technology, perhaps the painter can use spray equipment as
opposed to a brush and complete on the baseline finish day (Day 3).
This may also impact cost.
•
Man-load the task with additional workers (perhaps at increased cost)
to save the baseline duration, or at least compress duration. It is a
matter for management to reconcile estimating practices that 24 manhours were estimated for the job when the performing organization
provided a higher estimate once the task was underway and more
information was known. Of course this scenario that sooner or later
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the maximum amount of productive resources will have already been
added to the job and adding more resources will decrease productivity.
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For information regarding Earned Value Management Systems, Program Office
functionality and scheduling management, please contact:
CelerisSystems
3335 East Mira Loma Ave, Suite 143
Anaheim, California 92806
Toll Free in the United States
+1 800-760-0560 ext 706
Outside the United States:
+1 714-813-4025
©2008 CelerisSystems